Various machines have been proposed for packaging or "bagging" rows of round bales of hay or the like in long tubes of plastic film, which are tied off at the ends to provide a sealed bag containing the bales. This packaging of bales in weather sheaths protects the bales, minimizes their oxidation and weathering of the their outer layers, and eliminates unwanted moisture penetration.
With the known bale bagging machines, a tube of plastic film is retained in a shirred state on a rigid cylinder and is drawn off the cylinder onto bales as the bales are passed through the cylinder. With any such machine, the tube must be significantly larger in diameter than the bale, since the tube must be stored on the outside of the rigid cylinder that is itself large enough to pass over the bale. The cylinder itself must be sufficiently large to accommodate the usual deformation of the bale into an oval shape through natural settling.
With bales packed in a relatively loose tube, there is enough air surrounding the bales that noticeable oxidation can take place. In addition, a loose tube will flap in the wind, so that it must be relatively strong to resist wind damage. Consequently, the ability to fit a tube snugly over a round bale will bring with it a number of advantages. For example, with a tight tube, potential oxidation of the feed and wind damage to the tube are significantly reduced. Because the tight tube may be made smaller and of a thinner material due to the lower strength requirements, tube costs are also reduced.